From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7716EECAA25 for ; Thu, 25 Aug 2022 18:38:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243056AbiHYSiR convert rfc822-to-8bit (ORCPT ); Thu, 25 Aug 2022 14:38:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237742AbiHYSiN (ORCPT ); Thu, 25 Aug 2022 14:38:13 -0400 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51F7597B0C for ; Thu, 25 Aug 2022 11:38:12 -0700 (PDT) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-213-vv3swLJCMT6Ji3unTrfcKg-1; Thu, 25 Aug 2022 19:38:09 +0100 X-MC-Unique: vv3swLJCMT6Ji3unTrfcKg-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Thu, 25 Aug 2022 19:38:08 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.040; Thu, 25 Aug 2022 19:38:08 +0100 From: David Laight To: "netdev@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: ip netns exec namespace ls -l /proc/pid/fd prepends "/root" to the filename. Thread-Topic: ip netns exec namespace ls -l /proc/pid/fd prepends "/root" to the filename. Thread-Index: Adi4sCQiWHPDQxzJSJeo8ZJGzIAAZg== Date: Thu, 25 Aug 2022 18:38:08 +0000 Message-ID: <4c5a2ef5827f471cba84a7c74279f53a@AcuMS.aculab.com> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If a process inside a network namespace calls readlink() on /proc/pid/fd/n (for any pid) then the returned string is prefixed by "/root". So you get "/root/sys/console" or "/root/var/log/fred" etc. There seems to be an extra call to prepend_name() called from prepend_path() from d_path(). This seems decidedly wrong, especially since /root usually exists. Even it is were reporting a file outside a chroot (opened before the chroot) prepending "/root" would be wrong. Kernel is 5.10.132 (LTS before the retbleed breakages!) David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)